i40iw: Improve CM node lookup time on connection setup

Currently all CM nodes involved in a connection are
maintained in a connected_node list per dev. During
connection setup, we need to search this every time
we receive a packet on the iWARP LAN Queue (ILQ) and
this can be pretty inefficient for large number of
connections.

Fix this by organizing the CM nodes in two lists -
accelerated list and non-accelerated list. The search
on ILQ receive would be limited to only non accelerated
nodes. When a node moves to RTS, it is added to the
accelerated list.

Benchmarking ucmatose 16k connections shows a 20%
improvement in test completion time.
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/i40iw/i40iw.h

@@ -564,7 +564,8 @@ struct i40iw_cm_node *i40iw_find_node(struct i40iw_cm_core *cm_core,
 				      u32 *rem_addr,
 				      u16 loc_port,
 				      u32 *loc_addr,
-				      bool add_refcnt);
+				      bool add_refcnt,
+				      bool accelerated_list);
 
 enum i40iw_status_code i40iw_hw_flush_wqes(struct i40iw_device *iwdev,
 					   struct i40iw_sc_qp *qp,

drivers/infiniband/hw/i40iw/i40iw_cm.h

@@ -341,7 +341,7 @@ struct i40iw_cm_node {
 	int accept_pend;
 	struct list_head timer_entry;
 	struct list_head reset_entry;
-	struct list_head connected_entry;
+	struct list_head teardown_entry;
 	atomic_t passive_state;
 	bool qhash_set;
 	u8 user_pri;
@@ -403,7 +403,8 @@ struct i40iw_cm_core {
 	struct i40iw_sc_dev *dev;
 
 	struct list_head listen_nodes;
-	struct list_head connected_nodes;
+	struct list_head accelerated_list;
+	struct list_head non_accelerated_list;
 
 	struct timer_list tcp_timer;
 

drivers/infiniband/hw/i40iw/i40iw_utils.c

@@ -1407,7 +1407,7 @@ struct i40iw_sc_qp *i40iw_ieq_get_qp(struct i40iw_sc_dev *dev,
 	rem_port = ntohs(tcph->source);
 
 	cm_node = i40iw_find_node(&iwdev->cm_core, rem_port, rem_addr, loc_port,
-				  loc_addr, false);
+				  loc_addr, false, true);
 	if (!cm_node)
 		return NULL;
 	iwqp = cm_node->iwqp;